From 1ec7032ad517714108cc53a6ee7067276ca21e80 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Mon, 20 Apr 2015 14:34:57 +0200 Subject: [PATCH] clk: tegra: Add fixed factor peripheral clock type Some of the peripheral clocks on Tegra are derived from one of the top- level PLLs with a fixed factor. Support these clocks by implementing the ->enable() and ->disable() callbacks using the peripheral clock register banks and the ->recalc_rate() by dividing the parent rate by the fixed factor. Signed-off-by: Thierry Reding --- drivers/clk/tegra/Makefile | 1 + drivers/clk/tegra/clk-periph-fixed.c | 120 +++++++++++++++++++++++++++ drivers/clk/tegra/clk.h | 17 ++++ 3 files changed, 138 insertions(+) create mode 100644 drivers/clk/tegra/clk-periph-fixed.c diff --git a/drivers/clk/tegra/Makefile b/drivers/clk/tegra/Makefile index 97984c503bbb..33fd0938d79e 100644 --- a/drivers/clk/tegra/Makefile +++ b/drivers/clk/tegra/Makefile @@ -3,6 +3,7 @@ obj-y += clk-audio-sync.o obj-y += clk-dfll.o obj-y += clk-divider.o obj-y += clk-periph.o +obj-y += clk-periph-fixed.o obj-y += clk-periph-gate.o obj-y += clk-pll.o obj-y += clk-pll-out.o diff --git a/drivers/clk/tegra/clk-periph-fixed.c b/drivers/clk/tegra/clk-periph-fixed.c new file mode 100644 index 000000000000..c57dfb037b10 --- /dev/null +++ b/drivers/clk/tegra/clk-periph-fixed.c @@ -0,0 +1,120 @@ +/* + * Copyright (c) 2015, NVIDIA CORPORATION. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#include + +#include "clk.h" + +static inline struct tegra_clk_periph_fixed * +to_tegra_clk_periph_fixed(struct clk_hw *hw) +{ + return container_of(hw, struct tegra_clk_periph_fixed, hw); +} + +static int tegra_clk_periph_fixed_is_enabled(struct clk_hw *hw) +{ + struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw); + u32 mask = 1 << (fixed->num % 32), value; + + value = readl(fixed->base + fixed->regs->enb_reg); + if (value & mask) { + value = readl(fixed->base + fixed->regs->rst_reg); + if ((value & mask) == 0) + return 1; + } + + return 0; +} + +static int tegra_clk_periph_fixed_enable(struct clk_hw *hw) +{ + struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw); + u32 mask = 1 << (fixed->num % 32); + + writel(mask, fixed->base + fixed->regs->enb_set_reg); + + return 0; +} + +static void tegra_clk_periph_fixed_disable(struct clk_hw *hw) +{ + struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw); + u32 mask = 1 << (fixed->num % 32); + + writel(mask, fixed->base + fixed->regs->enb_clr_reg); +} + +static unsigned long +tegra_clk_periph_fixed_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw); + unsigned long long rate; + + rate = (unsigned long long)parent_rate * fixed->mul; + do_div(rate, fixed->div); + + return (unsigned long)rate; +} + +static const struct clk_ops tegra_clk_periph_fixed_ops = { + .is_enabled = tegra_clk_periph_fixed_is_enabled, + .enable = tegra_clk_periph_fixed_enable, + .disable = tegra_clk_periph_fixed_disable, + .recalc_rate = tegra_clk_periph_fixed_recalc_rate, +}; + +struct clk *tegra_clk_register_periph_fixed(const char *name, + const char *parent, + unsigned long flags, + void __iomem *base, + unsigned int mul, + unsigned int div, + unsigned int num) +{ + const struct tegra_clk_periph_regs *regs; + struct tegra_clk_periph_fixed *fixed; + struct clk_init_data init; + struct clk *clk; + + regs = get_reg_bank(num); + if (!regs) + return ERR_PTR(-EINVAL); + + fixed = kzalloc(sizeof(*fixed), GFP_KERNEL); + if (!fixed) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.flags = flags; + init.parent_names = parent ? &parent : NULL; + init.num_parents = parent ? 1 : 0; + init.ops = &tegra_clk_periph_fixed_ops; + + fixed->base = base; + fixed->regs = regs; + fixed->mul = mul; + fixed->div = div; + fixed->num = num; + + fixed->hw.init = &init; + + clk = clk_register(NULL, &fixed->hw); + if (IS_ERR(clk)) + kfree(fixed); + + return clk; +} diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h index 3ef530a8989d..7264f17e269e 100644 --- a/drivers/clk/tegra/clk.h +++ b/drivers/clk/tegra/clk.h @@ -516,6 +516,23 @@ struct clk *tegra_clk_register_periph_gate(const char *name, const char *parent_name, u8 gate_flags, void __iomem *clk_base, unsigned long flags, int clk_num, int *enable_refcnt); +struct tegra_clk_periph_fixed { + struct clk_hw hw; + void __iomem *base; + const struct tegra_clk_periph_regs *regs; + unsigned int mul; + unsigned int div; + unsigned int num; +}; + +struct clk *tegra_clk_register_periph_fixed(const char *name, + const char *parent, + unsigned long flags, + void __iomem *base, + unsigned int mul, + unsigned int div, + unsigned int num); + /** * struct clk-periph - peripheral clock *